Hello Atrenas
There is usually no refund for Supersaver tickets whose route is actually covered by a tourist travel pass.
You can still try, however:
https://www.sbb.ch/en/help-and-contact/refunds-compensation/refunds-compensation/refund-form.html
You must certainly provide a copy of your BO Pass.
If the ticket is refunded, it would mean a courtesy by SBB, there is no obligation, whatsoever.
Kind regards,
Roland